Research on this project has to do with synthetic oxygen carriers of metalloporphyrins, chiefly iron porphyrins. The ultimate goal of the project is to learn enough about the nature of these systems to be able to design and prepare better molecular oxygen carriers. At present, our research is directed towards the "capped" porphyrin iron(II) complexes prepared by Baldwin. We are investigating the steric and the electronic factors which contribute to the oxygen affinity in these systems. Work is also in progress to study the carbon monoxide affinity of these complexes. Since the carbon monoxide attached to iron inside the cap must be bent, we expect this system to closely resemble that of the natural protein where the Fe-C-O bond is said to be bent.